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MC 307 Pressure Relief Vent

This vent meets the “leaks less than one gallon” Model and Description
surge requirements of 178.345.10 (b) (3) (i).
9˝ swivel radius

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5 /4˝

4 8˝
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14˝ overall
MC-307BT
(GE00500 - 25#) (GE01500 - 30#) (GE02500 - 35#)
(GE03500 - Special setting, consult with Girard)
Vent with a 3” swivel nut. Mounts on a 3” nipple and seals
against a solid Teflon® gasket.
7 lbs. with accessories / 5 lbs., 8 oz. without

9˝ swivel radius

5 4˝
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3˝ O. D.
14˝ overall
MC-307ST
(GE20500 - 25#) (GE21500 - 30#) (GE22500 - 35#)
(GE23500 - Special setting, please specify)
FUNCTION Stub end vent. Lower housing ends in a straight stub end.
Welds to the dome cover.
The MC 307 Pressure Relief Vent is a stainless steel,
pressure actuated unit that is engineered to limit excessive MC-307MT
internal pressure to 130 percent of tank design. The (GE30500 - 25#) (GE31500 - 30#) (GE32500 - 35#)
standard model vent set at 25 PSIG will exhaust 26,700 (GE33500 - Special setting, consult with Girard)
SCFH at 32.5 PSIG and conforms to the emergency Same as the above, but the stub end is on an 18 degree angle
venting requirement code for MC 307 tanks having a total to conform to the curvature of the dome cover. Note: 3/4” and
exposed surface area up to 700 square feet. 1/4” NPT tap are not available in this style.

5 lbs., 10oz with accessories / 4 lbs., 2 oz. without
The stainless steel valve seat is equipped with a
replaceable Tef-O-Sil O-Ring. The unit doubles as an 9˝ swivel radius
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unloading device, since the valve body is tapped ⁄4”
NPT to accommodate the addition of inlet fittings for
air unloading of transports. Provision is also made for a
pressure gauge to be attached to the vent body.
5 1 4˝
An optional incorporation of a small vacuum section in
the valve seat is also available upon request. It should
be noted that this section, due to its limited size, may
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not be adequate enough to prohibit tank implosion. For 6 /4˝ O. D.
additional vacuum protection, refer to “Girard Magnetic 14˝ overall
Vacuum Breakers” for tank transports. MC-307FT
(GE10500 - 25#) (GE11500 - 30#) (GE12500 - 35#)
The entire vent is designed to be easily removed from the (GE13500 - Special setting, consult with Girard)
tank vehicle for inspection and cleaning.
Vent with a 3” TTMA drilled tank truck flange. Mounts to a 3”
TTMA drilled companion flange on the transport. Supplied with a
Teflon® envelope flange gasket.
5 lbs., 10oz with accessories / 4 lbs., 2 oz. without

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